Added back the stack underflow detection. It got lost when I updated the code from AVRASM2 to XC8 compiler.
ATMEGA: Add stack underflow check
PIC18: BLOCK EDIT CORE
Had to revert INTERPRET and re-introduce ABORT for unknown words. It did not work like I was thinking with blocks. Also blocks24.fs was updated to work. There is a new word EXECUTE? to prevent potentially unknown words from aborting the evaluation of a block. execute? -mark marker -mark
PIC24: Revert to use ABORT in INTERPRET. Fixed BLOCK words
PIC18: put back ABORT for unkown words
PIC18: BLOCK EDIT
PIC18: Remove DO LOOP